Enhance version syntax for get command

[roxblnfk]

What was changed

• Added mago binary to the package registry
• Enhanced the get command with version syntax support for software packages
• Improved validation and consideration of stability, OS, and architecture flags in get command
• Added documentation describing the new version syntax in README
• Added guidelines for Claude Code context

Why?

This PR introduces support for the mago binary and enhances the
package management capabilities of dload. The version syntax support
allows users to specify more precise version requirements when
downloading packages, while the improved flag validation ensures
better compatibility across different operating systems and
architectures. The documentation updates help users understand the
new functionality, and the guidelines provide better context for
future development work.

[codecov]

Codecov Report

❌ Patch coverage is 0% with 27 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/Command/Get.php	0.00%	27 Missing ⚠️

Files with missing lines	Coverage Δ	Complexity Δ
src/Command/Get.php	0.00% <0.00%> (ø)	14.00 <10.00> (+7.00)

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.